Semiconductor processing in the fabrication of integrated circuitry involves the deposition of layers on semiconductor substrates. Exemplary processes include chemical vapor deposition (CVD) and atomic layer deposition (ALD). CVD and ALD can be conducted within chambers which retain a single substrate upon a wafer holder or susceptor. Multiple substrate chambers might also be utilized. One or more precursor gases are typically provided to a showerhead within the chamber which is intended to uniformly provide the reactant gases substantially homogenously over the outer surface of the substrate. The precursors react or otherwise manifest in a deposition of a suitable layer atop the substrate. Plasma enhancement may or may not be utilized. If plasma enhancement is utilized, the plasma can be generated and maintained either directly within the chamber or remotely therefrom.
One commonly utilized insulative or dielectric material in semiconductor fabrication is silicon dioxide.